TWI426551B - Three-dimensional metal oxide electrodes and fabrication method thereof - Google Patents

Description

Stereo metal oxide electrode and method of manufacturing same

The present invention relates to an electrode structure, and more particularly to a three-dimensional metal oxide electrode and a method of manufacturing the same.

At present, most of the element electrode structures used are planar. For today's energy-related components, the insufficient surface area of the planar electrode may cause the speed of component current collection to decrease and affect the overall efficiency. The development of a three-dimensional conductive electrode having a three-dimensional structure can reduce the time for electrons to be transmitted to the electrodes to improve efficiency.

However, in the current research, such an electrode structure cannot be produced in a simple manner, and the main reason is that a nanostructure having high electric properties and high stability cannot be produced for forming an element electrode. According to the commonly used metal wire, when the wire diameter of the metal nanowire is less than 500 nm, the chemical stability and electronic properties become very unstable, and the structural thermal stability of the metal wire is not good, and it is easy to The disintegration of the component post-processing process causes the entire group of components to fail, so the study of using metal materials as stereoscopic conductive electrodes has encountered a large bottleneck.

In recent years, with the rapid development of research on conductive metal oxide materials, the current electrical resistivity of metal oxide materials has been quite close to that of metal materials, and the physical properties of oxide materials, whether in chemical stability or after nanocrystallization, There is no significant variation, and the transparent region of the visible light, so that more and more electronic products use highly conductive metal oxides as the electrode material of the components. However, in addition to the use of patterned chemical etching techniques, it is difficult to convert a planarized film into a bulk structure. Therefore, there has been no literature discussion on the application of a three-dimensional electrode.

One embodiment of the present invention provides a three-dimensional metal oxide electrode comprising: a metal oxide template; and a halogen-doped metal oxide film coated on the metal oxide template.

An embodiment of the present invention provides a method for manufacturing a three-dimensional metal oxide electrode, comprising: providing a metal oxide template; atomizing an aqueous solution containing a metal ion and a halogen dopant to form an aerosol; mixing the gas suspension And a gas to form a gas suspension gas stream; and introducing the gas suspension gas stream to the metal oxide template to form a halogen-doped metal oxide film on the metal oxide template.

In the present invention, a nanostructure such as zinc oxide is used as a template, and a nanostructure (line, column, tube, spiral, etc.) having a large area such as zinc oxide is produced by a simple chemical method at a low temperature, and then highly conductive by a chemical spray method. Metal oxide (such as fluorine-doped tin oxide) film material is sprayed on, and the two-stage process is used to produce a highly adjustable and highly conductive three-dimensional electrode structure, which can be widely applied to energy-related electronic components. Improve component performance.

The invention utilizes a low-temperature aqueous solution process to prepare a nanostructure such as zinc oxide as a template for a three-dimensional structure electrode, and to prepare a nanometer having different surface topography such as zinc oxide by controlling the concentration of the solution, the process temperature and the growth time. The structure (column, tube) is sprayed with a highly conductive metal oxide material such as a zinc oxide nanostructure to reduce the surface resistance value from 500 MΩ to the order of 100 Ω. The sputtering method can improve the conductivity and increase the coverage area by adjusting the doping amount of the dopant in the metal oxide and the process temperature. Applying such a three-dimensional electrode structure to the currently used solar cell structure can shorten the time of electron transfer, and since the outer layer of the three-dimensional electrode material is also a metal oxide, the semiconductor energy gap can be fine-tuned according to the component requirements. The action makes the component design have a lower junction loss, which will greatly help the energy related components.

The invention utilizes an easy-to-manage nano structure as a template, and deposits a conductive oxide material on the template by using the atmosphere, and can directly and efficiently produce a multi-dimensional conductive electrode in a large amount, and can accurately control the conductivity of the multi-dimensional electrode by using the coating parameter. It can improve the performance of the application components while maintaining high stability performance.

The above described objects, features and advantages of the present invention will become more apparent and understood.

One embodiment of the present invention provides a ternary metal oxide electrode comprising a metal oxide template and a halogen-doped metal oxide film overlying the metal oxide template.

The above metal oxide template may be composed of zinc oxide, aluminum oxide, cerium oxide or titanium dioxide. The metal oxide template may be in the form of particles, wires, columns, tubes, needles, spheres, sheets or polyhedrons. The size of the metal oxide template is generally between 5 and 50,000 nm, preferably between 10 and 5,000 nm.

The metal oxide thin film may be composed of zinc oxide, tin oxide, copper oxide, gallium oxide or indium oxide. The thickness of the metal oxide film is generally between 5 and 500 nm. The three-dimensional metal oxide electrode of the present invention can be applied to a solar cell.

One embodiment of the present invention provides a method of fabricating a three-dimensional metal oxide electrode, comprising the following steps. First, a metal oxide template is provided. Next, an aqueous solution containing a metal ion and a halogen dopant is atomized to form an aerosol. Thereafter, the gas suspension is suspended with a gas to form a gas suspension gas stream. Next, a gas suspension gas stream is introduced to the metal oxide template to form a halogen-doped metal oxide film on the metal oxide template.

The method for producing the above metal oxide template is disclosed below. First, a specific ratio of metal salts and corresponding chemical reagents are mixed to prepare an aqueous solution. The above metal salts may include zinc nitrate, aluminum alkoxide, tetrahexyl phthalate or titanium tetrachloride. When the metal salt used is zinc nitrate, the corresponding chemical reagent may be hexamethyltetramine. When the metal salt used is aluminum tri-sec-butoxide (ASB), the corresponding chemical reagent may be ethanol or toluene. When the metal salt used is tetrahexylidene, the corresponding chemical reagent may be water or sulfuric acid. When the metal salt used is titanium tetrachloride, the corresponding chemical reagent may be hydrochloric acid or nitric acid. Next, a test piece covered with, for example, a zinc oxide buffer layer is provided as a seeding layer for subsequent growth of, for example, zinc oxide. Thereafter, the reaction is carried out in an environment of, for example, less than 100 ° C to prepare a nanostructure having a specific form such as zinc oxide.

The above metal oxide template may be composed of zinc oxide, aluminum oxide, cerium oxide or titanium dioxide. The metal oxide template may be in the form of particles, wires, columns, tubes, needles, spheres, sheets or polyhedrons. The size of the metal oxide template is generally between 5 and 50,000 nm, preferably between 10 and 5,000 nm.

The above-described nanostructure such as zinc oxide is used as a template, and a metal oxide film can be deposited on the structure by, for example, chemical spraying. The chemical spraying method used is as follows. A metal precursor containing, for example, tin ions and a halogen-doped salt precursor are placed in a container as an aqueous solution, and a carrier gas is simultaneously introduced into the micro-droplet mist. After the atomizer is used to uniformly mix the salt precursor with the carrier gas, the flow rate and flow rate of the atomizer are adjusted to obtain a gas suspension gas stream having a uniform size, which is directly introduced into the heated metal. The oxide template is subjected to chemical vapor deposition to form a transparent conductive film such as a main component of tin oxide, and the size of the suspension rubber can be further adjusted by providing an auxiliary heater to the periphery of the deposition substrate to obtain different films. Surface properties. The oscillating frequency of the above atomizer can be between 1.5KHz and 2.6MHz, and the same effect can be achieved by a precision nozzle (<10μm).

In the above aqueous solution, the metal ions may include zinc ions, tin ions, copper ions, gallium ions or indium ions, and the molar percentage of the halogen dopant is generally between 3 and 75%.

The size of the above suspension rubber is generally between 0.1 and 10 microns. The gas carrying the aerogel may include air, oxygen, nitrogen or a mixed gas of nitrogen and oxygen.

The flow rate of the above air suspension gas flow is generally between 1 and 30 L/min. The temperature at which the gas suspension gas is introduced into the metal oxide template is generally between 300 and 500 °C.

The metal oxide thin film may be composed of zinc oxide, tin oxide, copper oxide, gallium oxide or indium oxide. The thickness of the metal oxide film is generally between 5 and 500 nm.

The metal oxide template of the present invention can be removed by, for example, chemical etching, plasma etching, or high temperature gas evaporation.

In the present invention, a nanostructure such as zinc oxide is used as a template, and a nanostructure (line, column, tube, spiral, etc.) having a large area such as zinc oxide is produced by a simple chemical method at a low temperature, and then highly conductive by a chemical spray method. Metal oxide (such as fluorine-doped tin oxide) film material is sprayed on, and the two-stage process is used to produce a highly adjustable and highly conductive three-dimensional electrode structure, which can be widely applied to energy-related electronic components. Improve component performance.

The invention utilizes a low-temperature aqueous solution process to prepare a nanostructure such as zinc oxide as a template for a three-dimensional structure electrode, and to prepare a nanometer having different surface topography such as zinc oxide by controlling the concentration of the solution, the process temperature and the growth time. The structure (column, tube) is sprayed with a highly conductive metal oxide material such as a zinc oxide nanostructure to reduce the surface resistance value from 500 MΩ to the order of 100 Ω. The sputtering method can improve the conductivity and increase the coverage area by adjusting the doping amount of the dopant in the metal oxide and the process temperature. Applying such a three-dimensional electrode structure to the currently used solar cell structure can shorten the time of electron transfer, and since the outer layer of the three-dimensional electrode material is also a metal oxide, the semiconductor energy gap can be fine-tuned according to the component requirements. The action makes the component design have a lower junction loss, which will greatly help the energy related components.

The invention utilizes an easy-to-manage nano structure as a template, and deposits a conductive oxide material on the template by using the atmosphere, and can directly and efficiently produce a multi-dimensional conductive electrode in a large amount, and can accurately control the conductivity of the multi-dimensional electrode by using the coating parameter. It can improve the performance of the application components while maintaining high stability performance.

[Examples] [Example 1] Metal oxide template (linear) preparation (1)

First, 0.005 mol of zinc nitrate and 0.005 mol of hexamethyltetramine were mixed to prepare an aqueous solution. Next, a test piece covered with a zinc oxide buffer layer was provided. Thereafter, the reaction was carried out in an environment of a temperature of 95 ° C to prepare a linear zinc oxide nanostructure. The size of the zinc oxide template is greater than 3,000 nm, as shown in Figure 1. Figure 1 is an electron microscopic analysis of a linear zinc oxide template.

[Example 2] Metal oxide template (columnar) preparation (2)

First, 0.01 mol of zinc nitrate and 0.01 mol of hexamethyltetramine were mixed to prepare an aqueous solution. Next, a test piece covered with a zinc oxide buffer layer was provided. Thereafter, the reaction was carried out in an environment of a temperature of 75 ° C to prepare a columnar zinc oxide nanostructure. The size of the zinc oxide template is greater than 500 nm, as shown in Figure 2. Figure 2 is an electron microscopic analysis of a columnar zinc oxide template.

[Comparative Example 1] Preparation of metal oxide film material (0% fluorine doping)

First, an aqueous solution containing 0.5 mol of SnCl ₂ ‧5H ₂ O was prepared, and the aqueous solution was placed in a container. In addition, the air is simultaneously introduced into the micro-droplet atomizer, and the SnCl ₂ ‧5H ₂ O is uniformly mixed with the air by the atomizer, and the flow rate of the atomizer is adjusted to be 20 L/min to obtain a size. Hanging gas flow in 5~8 microns.

[Example 3] Preparation of metal oxide thin film materials (1) (10% fluorine doping)

First, 0.5 mol of SnCl ₂ ‧5H ₂ O and 0.05 mol of NH ₄ F dopant were mixed to prepare an aqueous solution containing Sn(OH) ₄ , and the aqueous solution was placed in a container. In addition, the air is simultaneously introduced into the micro-droplet atomizer, and the Sn(OH) _{4 is} uniformly mixed with the air by the atomizer, and the flow rate of the atomizer is adjusted to be 20 L/min to obtain a size between 5~8 micron gas suspension gas flow.

[Embodiment 4] Preparation of metal oxide thin film materials (2) (25% fluorine doping)

First, 0.5 mol of SnCl ₂ ‧5H ₂ O and 0.125 mol of NH ₄ F dopant were mixed to prepare an aqueous solution containing Sn(OH) ₄ , and the aqueous solution was placed in a container. In addition, the air is simultaneously introduced into the micro-droplet atomizer, and the Sn(OH) _{4 is} uniformly mixed with the air by the atomizer, and the flow rate of the atomizer is adjusted to be 20 L/min to obtain a size between 5~8 micron gas suspension gas flow.

[Embodiment 5] Preparation of metal oxide thin film material (3) (35% fluorine doping)

First, 0.5 mol of SnCl ₂ ‧5H ₂ O and 0.175 mol of NH ₄ F dopant were mixed to prepare an aqueous solution containing Sn(OH) ₄ , and the aqueous solution was placed in a container. In addition, the air is simultaneously introduced into the micro-droplet atomizer, and the Sn(OH) _{4 is} uniformly mixed with the air by the atomizer, and the flow rate of the atomizer is adjusted to be 20 L/min to obtain a size between 5~8 micron gas suspension gas flow.

[Embodiment 6] Preparation of metal oxide thin film materials (4) (50% fluorine doping)

First, 0.5 mol of SnCl ₂ ‧5H ₂ O and 0.25 mol of NH ₄ F dopant were mixed to prepare an aqueous solution containing Sn(OH) ₄ , and the aqueous solution was placed in a container. In addition, the air is simultaneously introduced into the micro-droplet atomizer, and the Sn(OH) _{4 is} uniformly mixed with the air by the atomizer, and the flow rate of the atomizer is adjusted to be 20 L/min to obtain a size between 5~8 micron gas suspension gas flow.

[Embodiment 7] Preparation of metal oxide film material (5) (75% fluorine doping)

First, 0.5 mol of SnCl ₂ ‧5H ₂ O and 0.375 mol of NH ₄ F dopant were mixed to prepare an aqueous solution containing Sn(OH) ₄ , and the aqueous solution was placed in a container. In addition, the air is simultaneously introduced into the micro-droplet atomizer, and the Sn(OH) _{4 is} uniformly mixed with the air by the atomizer, and the flow rate of the atomizer is adjusted to be 20 L/min to obtain a size between 5~8 micron gas suspension gas flow.

[Embodiment 8] Metal oxide electrode preparation

The gas suspension gas streams prepared in Comparative Example 1 and Examples 3 to 7 were directly introduced into a heated metal oxide template for chemical vapor deposition to form a transparent conductive film having a main component of tin oxide. The above-mentioned atomizer has an oscillation frequency of 1,000 kHz. The temperature of the introduced air suspension gas stream to the heated structured test piece was 400 °C. The above-described tin oxide transparent conductive film was subjected to a resistivity test, and the results are shown in Fig. 3. It can be seen from Fig. 3 that the conductivity of the film becomes better as the doping concentration of the fluoride ion increases. When the concentration of the fluoride ion reaches 10%, the conductivity of the film reaches saturation, and the optimum resistivity value is about 6.2×10. ^-4 Ω-cm.

[Embodiment 9] Coating of metal oxide electrodes

The fluorine-doped tin oxide (FTO) thin film materials prepared in Examples 3 to 7 were deposited on the zinc oxide nanostructures prepared in Examples 1 and 2 by sputtering, and the fluorine-doped tin oxide was formed on the surface morphology. FTO) materials can be well coated on zinc oxide, as shown in Figures 4-5. The thickness of the coating is 20 nm (Fig. 4) and 50 nm (Fig. 5). Under the analysis of the transmission electron microscope, it can be clearly seen that the fluorine-doped tin oxide (FTO) material was successfully sprayed on the zinc oxide nanowire (Fig. 4) and the nanocolumn (Fig. 5). .

[Embodiment 9] Electrical test of metal oxide electrodes

Fig. 6 shows that the resistance value of the zinc oxide nanostructure is 100 M?. Figure 7 shows that the measured resistance of the highly conductive three-dimensional electrode structure is about 10KΩ~1KΩ (coated with fluorine-doped tin oxide (FTO) 20nm and 40nm, respectively). It can be seen, the present invention is coated a fluorine-doped tin oxide (FTO) perspective conductive electrode structure can improve rate of ¹⁰⁶ times. If a 100 nm fluorine-doped tin oxide (FTO) film is coated on the zinc oxide nanostructure, the resistance can be reduced to 100 Ω. Therefore, the zinc oxide nanostructure can be used as a template for the three-dimensional electrode, and the high-conductive oxide material can be sprayed to successfully produce a three-dimensional high-surface electrode structure with high conductivity. At the same time, since the crystal structure between the oxide materials is easily adjusted, the coating efficiency of the film can be improved to achieve a high film density and low resistance. From the electrical measurement data, the resistance value of the coated conductive oxide nanowire is about 100 Ω, and the electrode structure can improve the current collecting performance of the semiconductor device.

The invention utilizes the atmospheric spraying method to deposit the conductive oxide, and the polycrystalline metal oxide nanostructure prepared by the low temperature can be used to fabricate a multi-dimensional conductive electrode, and the conductivity of the multi-dimensional electrode can be improved by controlling the thickness of the transparent conductive film. The resistance change rate can reach 10 ⁶ times and the specification can reach 100Ω. It can be applied to energy-related products and is a new high-efficiency, high-surface-conducting electrode structure.

While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the invention may be modified and retouched without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application attached.

Figure 1 is an electron microscopic analysis of a linear zinc oxide template of the present invention.

Figure 2 is an electron microscopic analysis of a columnar zinc oxide template of the present invention.

Figure 3 is a graph showing the resistivity of a fluorine ion doped tin oxide film of the present invention.

Figure 4 is an electron microscopic analysis of a linear zinc oxide template coated with a fluorine-doped tin oxide (FTO) film of the present invention.

Fig. 5 is an electron microscopic analysis of a columnar zinc oxide template coated with a fluorine-doped tin oxide (FTO) film according to the present invention.

Figure 6 is an electrical test of the zinc oxide nanostructure of the present invention.

Figure 7 is an electrical test of the highly conductive three-dimensional electrode structure of the present invention.

Claims (20)

A three-dimensional metal oxide electrode comprising: a metal oxide template, wherein the metal oxide template is granular, linear, columnar, tubular, needle-shaped, spherical, flake or polyhedral; and a doped halogen A metal oxide film is coated on the metal oxide template. The three-dimensional metal oxide electrode according to claim 1, wherein the metal oxide template is composed of zinc oxide, aluminum oxide, cerium oxide or titanium dioxide. The three-dimensional metal oxide electrode according to claim 1, wherein the metal oxide template has a size of 5 to 50,000 nm. The three-dimensional metal oxide electrode according to claim 1, wherein the metal oxide template has a size of 10 to 5,000 nm. The three-dimensional metal oxide electrode according to claim 1, wherein the metal oxide film is composed of zinc oxide, tin oxide, copper oxide, gallium oxide or indium oxide. The three-dimensional metal oxide electrode according to claim 1, wherein the metal oxide film has a thickness of 5 to 500 nm. The three-dimensional metal oxide electrode according to claim 1, wherein the three-dimensional metal oxide electrode is applied to a solar cell. A method for manufacturing a three-dimensional metal oxide electrode, comprising: providing a metal oxide template; atomizing an aqueous solution containing a metal ion and a halogen dopant to form an aerosol; Mixing the aerosol with a gas to form a gas suspension gas stream; and introducing the aerosol gas stream to the metal oxide template to form a halogen-doped metal oxide film on the metal oxide template. The method for producing a three-dimensional metal oxide electrode according to claim 8, wherein the metal oxide template is composed of zinc oxide, aluminum oxide, cerium oxide or titanium oxide. The method for producing a three-dimensional metal oxide electrode according to claim 8, wherein the metal oxide template is in the form of a pellet, a wire, a column, a tube, a needle, a sphere, a sheet or a polyhedron. The method for producing a three-dimensional metal oxide electrode according to claim 10, wherein the metal oxide template has a size of 5 to 50,000 nm. The method for producing a three-dimensional metal oxide electrode according to claim 10, wherein the metal oxide template has a size of 10 to 5,000 nm. The method for producing a three-dimensional metal oxide electrode according to claim 8, wherein the metal ion comprises zinc ion, tin ion, copper ion, gallium ion or indium ion. The method for producing a three-dimensional metal oxide electrode according to claim 8, wherein the halogen dopant has a molar percentage of from 3 to 75%. The method for manufacturing a three-dimensional metal oxide electrode according to claim 8, wherein the size of the aerosol is between 0.1 and 10 μm. The method for producing a three-dimensional metal oxide electrode according to claim 8, wherein the gas comprises air, oxygen, nitrogen or a mixed gas of nitrogen and oxygen. The method for manufacturing a three-dimensional metal oxide electrode according to claim 8, wherein the flow rate of the air suspension gas is between 1 and 30 L/min. The method for producing a three-dimensional metal oxide electrode according to claim 8, wherein the temperature of the gas stream introduced into the aerosol is between 300 and 500 °C. The method for producing a three-dimensional metal oxide electrode according to claim 8, wherein the metal oxide film is made of zinc oxide, tin oxide, copper oxide, gallium oxide or indium oxide. The method for producing a three-dimensional metal oxide electrode according to claim 8, wherein the metal oxide film has a thickness of 5 to 500 nm.